Why isn't stevia used everywhere as a sweetener?

As I look at food packages these days, it's amazing to see the large amount of fake sweeteners along with loads of refined sugar in so many foods. After all, everyone has a partial (or whole) "sweet tooth", and manufacturers sell ore products when they make them taste good.

The only downside is that tasting good comes at a price. Generally, refined sugars are really bad for human health (my 2 cents, anyway), and have a load of calories. The solution has been to use artificial sweeteners as a replacement, which then have unnatural chemicals which I consider to be almost as bad (or worse) than refined sugar.

Where is the "sweet" answer then? How about low-calorie, low-glycemic sweeteners like agave nectar and stevia? The food manufacturers probably don't want to use these items due to cost (which can be high) and due to these alternatives being natural products (that can't be protected by patents and such). One thing is for sure -- stevia is a great and sweet alternative that's been used globally for centuries and it beats the pants off table sugar and bleached refined sugar. Try it if you can -- and you decide.